In order to perform valid and reliable research into the characteristics and mechanisms of early stage Alzheimer's disease (AD) and related dementias, it is imperative to have data available from a well-characterized cohort of patients. The cohort should have a broad range of levels of education and socioeconomic status as well as racial diversity. It should contain patients with symptoms across the spectrum of disease severity including preclinical AD and Mild Cognitive Impairment. A system must be in place for the reconsideration and annual update of diagnoses based on new clinical information such that a complete series of clinical impressions can be recorded over the course of the disease. Such a flexible system is also essential to accommodate and review cases of dementias other than AD such as the diagnostic criteria for Dementia with Lewy Bodies. The Clinical Core of the Alzheimer's Disease Research Center at the University of Pittsburgh fulfills these functions. The Clinical Core provides evaluation and follow-up to patients and control subjects followed in the Memory Disorders Clinic and enrolled in the ADRC Registry. Specifically, the Core provides a detailed evaluation of all patients and control subjects at study entry, and at annual evaluations until the subject drops from the project or dies. The Core also strives towards maximal participation in the autopsy program of the ADRC by providing longitudinal follow-up to these patients and controls. It is also responsible for providing clinical data, research subjects, training, and technical and scientific leadership for support of new and ongoing research at the Pittsburgh ADRC and associated local, regional, national, and international studies. The ADRC will continue outreach programs developed to provide care and support for members of the medically underserved inner-city populations through our satellite clinic, the Alzheimer Outreach Center, which is based in the predominantly African American Hill District of Pittsburgh. A second satellite clinic at the University of Virginia has been established and begins evaluating patients during the 1st year of the coming cycle. This satellite will recruit rural Caucasian and African American subjects with the goal of providing greater diversity to the ADRC cohort and greater participation in research from these underserved populations. External confirmation of the accuracy of the clinical diagnosis of AD is also vital to ensure that the evolving diagnostic procedures employed by the Clinical Core are appropriate. Autopsy confirmation of a clinical diagnosis of Probable AD was 91 % for all cases from the ADRC coming to autopsy during the current funding period.